Taxonomic Status and First Record of a Yellow-Flowered Astragalus (sect. Dissitiflori, Fabaceae) from Central Balkans.

A yellow-flowered Astragalus from section Dissitiflori DC. is reported for the first time for the flora of the central Balkan Peninsula, near the city of Dimitrovgrad (E Serbia). This finding significantly expands the known distribution range of yellow-flowered representatives of this group. The taxonomy and nomenclatural status of yellow-flowered taxa of Astragalus sect. Dissitiflori in Europe remain problematic and partly unresolved due to considerable morphological variation, overlapping morphological and chorological characters, limited molecular and ecological data, and an insufficient number of comparative studies. To clarify the taxonomic position of the newly discovered population, we provided a comparative overview of morphological characters of closely related taxa, determined the chromosome number (2n = 4x = 32), and provided data on habitat characteristics, ecology and population status. Based on the most recent taxonomic concepts, the population from Dimitrovgrad is referred to as Astragalus albicaulis. However, further comprehensive morphological, anatomical, palynological, karyological, and ecological studies are required for its precise taxonomic and nomenclatural delimitation within sect. Dissitiflori.